+++ /dev/null
-From 71cc849b7093bb83af966c0e60cb11b7f35cd746 Mon Sep 17 00:00:00 2001
-From: Paolo Bonzini <pbonzini@redhat.com>
-Date: Fri, 27 Nov 2020 09:18:20 +0100
-Subject: KVM: x86: Fix split-irqchip vs interrupt injection window request
-
-From: Paolo Bonzini <pbonzini@redhat.com>
-
-commit 71cc849b7093bb83af966c0e60cb11b7f35cd746 upstream.
-
-kvm_cpu_accept_dm_intr and kvm_vcpu_ready_for_interrupt_injection are
-a hodge-podge of conditions, hacked together to get something that
-more or less works. But what is actually needed is much simpler;
-in both cases the fundamental question is, do we have a place to stash
-an interrupt if userspace does KVM_INTERRUPT?
-
-In userspace irqchip mode, that is !vcpu->arch.interrupt.injected.
-Currently kvm_event_needs_reinjection(vcpu) covers it, but it is
-unnecessarily restrictive.
-
-In split irqchip mode it's a bit more complicated, we need to check
-kvm_apic_accept_pic_intr(vcpu) (the IRQ window exit is basically an INTACK
-cycle and thus requires ExtINTs not to be masked) as well as
-!pending_userspace_extint(vcpu). However, there is no need to
-check kvm_event_needs_reinjection(vcpu), since split irqchip keeps
-pending ExtINT state separate from event injection state, and checking
-kvm_cpu_has_interrupt(vcpu) is wrong too since ExtINT has higher
-priority than APIC interrupts. In fact the latter fixes a bug:
-when userspace requests an IRQ window vmexit, an interrupt in the
-local APIC can cause kvm_cpu_has_interrupt() to be true and thus
-kvm_vcpu_ready_for_interrupt_injection() to return false. When this
-happens, vcpu_run does not exit to userspace but the interrupt window
-vmexits keep occurring. The VM loops without any hope of making progress.
-
-Once we try to fix these with something like
-
- return kvm_arch_interrupt_allowed(vcpu) &&
-- !kvm_cpu_has_interrupt(vcpu) &&
-- !kvm_event_needs_reinjection(vcpu) &&
-- kvm_cpu_accept_dm_intr(vcpu);
-+ (!lapic_in_kernel(vcpu)
-+ ? !vcpu->arch.interrupt.injected
-+ : (kvm_apic_accept_pic_intr(vcpu)
-+ && !pending_userspace_extint(v)));
-
-we realize two things. First, thanks to the previous patch the complex
-conditional can reuse !kvm_cpu_has_extint(vcpu). Second, the interrupt
-window request in vcpu_enter_guest()
-
- bool req_int_win =
- dm_request_for_irq_injection(vcpu) &&
- kvm_cpu_accept_dm_intr(vcpu);
-
-should be kept in sync with kvm_vcpu_ready_for_interrupt_injection():
-it is unnecessary to ask the processor for an interrupt window
-if we would not be able to return to userspace. Therefore,
-kvm_cpu_accept_dm_intr(vcpu) is basically !kvm_cpu_has_extint(vcpu)
-ANDed with the existing check for masked ExtINT. It all makes sense:
-
-- we can accept an interrupt from userspace if there is a place
- to stash it (and, for irqchip split, ExtINTs are not masked).
- Interrupts from userspace _can_ be accepted even if right now
- EFLAGS.IF=0.
-
-- in order to tell userspace we will inject its interrupt ("IRQ
- window open" i.e. kvm_vcpu_ready_for_interrupt_injection), both
- KVM and the vCPU need to be ready to accept the interrupt.
-
-... and this is what the patch implements.
-
-Reported-by: David Woodhouse <dwmw@amazon.co.uk>
-Analyzed-by: David Woodhouse <dwmw@amazon.co.uk>
-Cc: stable@vger.kernel.org
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
-Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
-Tested-by: David Woodhouse <dwmw@amazon.co.uk>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
----
- arch/x86/include/asm/kvm_host.h | 1 +
- arch/x86/kvm/irq.c | 2 +-
- arch/x86/kvm/x86.c | 18 ++++++++++--------
- 3 files changed, 12 insertions(+), 9 deletions(-)
-
---- a/arch/x86/include/asm/kvm_host.h
-+++ b/arch/x86/include/asm/kvm_host.h
-@@ -1395,6 +1395,7 @@ int kvm_test_age_hva(struct kvm *kvm, un
- void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
- int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v);
- int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
-+int kvm_cpu_has_extint(struct kvm_vcpu *v);
- int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
- int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
- void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event);
---- a/arch/x86/kvm/irq.c
-+++ b/arch/x86/kvm/irq.c
-@@ -52,7 +52,7 @@ static int pending_userspace_extint(stru
- * check if there is pending interrupt from
- * non-APIC source without intack.
- */
--static int kvm_cpu_has_extint(struct kvm_vcpu *v)
-+int kvm_cpu_has_extint(struct kvm_vcpu *v)
- {
- u8 accept = kvm_apic_accept_pic_intr(v);
-
---- a/arch/x86/kvm/x86.c
-+++ b/arch/x86/kvm/x86.c
-@@ -3144,21 +3144,23 @@ static int kvm_vcpu_ioctl_set_lapic(stru
-
- static int kvm_cpu_accept_dm_intr(struct kvm_vcpu *vcpu)
- {
-+ /*
-+ * We can accept userspace's request for interrupt injection
-+ * as long as we have a place to store the interrupt number.
-+ * The actual injection will happen when the CPU is able to
-+ * deliver the interrupt.
-+ */
-+ if (kvm_cpu_has_extint(vcpu))
-+ return false;
-+
-+ /* Acknowledging ExtINT does not happen if LINT0 is masked. */
- return (!lapic_in_kernel(vcpu) ||
- kvm_apic_accept_pic_intr(vcpu));
- }
-
--/*
-- * if userspace requested an interrupt window, check that the
-- * interrupt window is open.
-- *
-- * No need to exit to userspace if we already have an interrupt queued.
-- */
- static int kvm_vcpu_ready_for_interrupt_injection(struct kvm_vcpu *vcpu)
- {
- return kvm_arch_interrupt_allowed(vcpu) &&
-- !kvm_cpu_has_interrupt(vcpu) &&
-- !kvm_event_needs_reinjection(vcpu) &&
- kvm_cpu_accept_dm_intr(vcpu);
- }
-
btrfs-tree-checker-enhance-chunk-checker-to-validate-chunk-profile.patch
btrfs-adjust-return-values-of-btrfs_inode_by_name.patch
btrfs-inode-verify-inode-mode-to-avoid-null-pointer-dereference.patch
-kvm-x86-fix-split-irqchip-vs-interrupt-injection-window-request.patch
arm64-pgtable-fix-pte_accessible.patch
arm64-pgtable-ensure-dirty-bit-is-preserved-across-pte_wrprotect.patch
alsa-hda-hdmi-use-single-mutex-unlock-in-error-paths.patch
+++ /dev/null
-From 71cc849b7093bb83af966c0e60cb11b7f35cd746 Mon Sep 17 00:00:00 2001
-From: Paolo Bonzini <pbonzini@redhat.com>
-Date: Fri, 27 Nov 2020 09:18:20 +0100
-Subject: KVM: x86: Fix split-irqchip vs interrupt injection window request
-
-From: Paolo Bonzini <pbonzini@redhat.com>
-
-commit 71cc849b7093bb83af966c0e60cb11b7f35cd746 upstream.
-
-kvm_cpu_accept_dm_intr and kvm_vcpu_ready_for_interrupt_injection are
-a hodge-podge of conditions, hacked together to get something that
-more or less works. But what is actually needed is much simpler;
-in both cases the fundamental question is, do we have a place to stash
-an interrupt if userspace does KVM_INTERRUPT?
-
-In userspace irqchip mode, that is !vcpu->arch.interrupt.injected.
-Currently kvm_event_needs_reinjection(vcpu) covers it, but it is
-unnecessarily restrictive.
-
-In split irqchip mode it's a bit more complicated, we need to check
-kvm_apic_accept_pic_intr(vcpu) (the IRQ window exit is basically an INTACK
-cycle and thus requires ExtINTs not to be masked) as well as
-!pending_userspace_extint(vcpu). However, there is no need to
-check kvm_event_needs_reinjection(vcpu), since split irqchip keeps
-pending ExtINT state separate from event injection state, and checking
-kvm_cpu_has_interrupt(vcpu) is wrong too since ExtINT has higher
-priority than APIC interrupts. In fact the latter fixes a bug:
-when userspace requests an IRQ window vmexit, an interrupt in the
-local APIC can cause kvm_cpu_has_interrupt() to be true and thus
-kvm_vcpu_ready_for_interrupt_injection() to return false. When this
-happens, vcpu_run does not exit to userspace but the interrupt window
-vmexits keep occurring. The VM loops without any hope of making progress.
-
-Once we try to fix these with something like
-
- return kvm_arch_interrupt_allowed(vcpu) &&
-- !kvm_cpu_has_interrupt(vcpu) &&
-- !kvm_event_needs_reinjection(vcpu) &&
-- kvm_cpu_accept_dm_intr(vcpu);
-+ (!lapic_in_kernel(vcpu)
-+ ? !vcpu->arch.interrupt.injected
-+ : (kvm_apic_accept_pic_intr(vcpu)
-+ && !pending_userspace_extint(v)));
-
-we realize two things. First, thanks to the previous patch the complex
-conditional can reuse !kvm_cpu_has_extint(vcpu). Second, the interrupt
-window request in vcpu_enter_guest()
-
- bool req_int_win =
- dm_request_for_irq_injection(vcpu) &&
- kvm_cpu_accept_dm_intr(vcpu);
-
-should be kept in sync with kvm_vcpu_ready_for_interrupt_injection():
-it is unnecessary to ask the processor for an interrupt window
-if we would not be able to return to userspace. Therefore,
-kvm_cpu_accept_dm_intr(vcpu) is basically !kvm_cpu_has_extint(vcpu)
-ANDed with the existing check for masked ExtINT. It all makes sense:
-
-- we can accept an interrupt from userspace if there is a place
- to stash it (and, for irqchip split, ExtINTs are not masked).
- Interrupts from userspace _can_ be accepted even if right now
- EFLAGS.IF=0.
-
-- in order to tell userspace we will inject its interrupt ("IRQ
- window open" i.e. kvm_vcpu_ready_for_interrupt_injection), both
- KVM and the vCPU need to be ready to accept the interrupt.
-
-... and this is what the patch implements.
-
-Reported-by: David Woodhouse <dwmw@amazon.co.uk>
-Analyzed-by: David Woodhouse <dwmw@amazon.co.uk>
-Cc: stable@vger.kernel.org
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
-Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
-Tested-by: David Woodhouse <dwmw@amazon.co.uk>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
----
- arch/x86/include/asm/kvm_host.h | 1 +
- arch/x86/kvm/irq.c | 2 +-
- arch/x86/kvm/x86.c | 18 ++++++++++--------
- 3 files changed, 12 insertions(+), 9 deletions(-)
-
---- a/arch/x86/include/asm/kvm_host.h
-+++ b/arch/x86/include/asm/kvm_host.h
-@@ -1220,6 +1220,7 @@ int kvm_test_age_hva(struct kvm *kvm, un
- void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
- int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v);
- int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
-+int kvm_cpu_has_extint(struct kvm_vcpu *v);
- int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
- int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
- void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event);
---- a/arch/x86/kvm/irq.c
-+++ b/arch/x86/kvm/irq.c
-@@ -49,7 +49,7 @@ static int pending_userspace_extint(stru
- * check if there is pending interrupt from
- * non-APIC source without intack.
- */
--static int kvm_cpu_has_extint(struct kvm_vcpu *v)
-+int kvm_cpu_has_extint(struct kvm_vcpu *v)
- {
- u8 accept = kvm_apic_accept_pic_intr(v);
-
---- a/arch/x86/kvm/x86.c
-+++ b/arch/x86/kvm/x86.c
-@@ -2866,21 +2866,23 @@ static int kvm_vcpu_ioctl_set_lapic(stru
-
- static int kvm_cpu_accept_dm_intr(struct kvm_vcpu *vcpu)
- {
-+ /*
-+ * We can accept userspace's request for interrupt injection
-+ * as long as we have a place to store the interrupt number.
-+ * The actual injection will happen when the CPU is able to
-+ * deliver the interrupt.
-+ */
-+ if (kvm_cpu_has_extint(vcpu))
-+ return false;
-+
-+ /* Acknowledging ExtINT does not happen if LINT0 is masked. */
- return (!lapic_in_kernel(vcpu) ||
- kvm_apic_accept_pic_intr(vcpu));
- }
-
--/*
-- * if userspace requested an interrupt window, check that the
-- * interrupt window is open.
-- *
-- * No need to exit to userspace if we already have an interrupt queued.
-- */
- static int kvm_vcpu_ready_for_interrupt_injection(struct kvm_vcpu *vcpu)
- {
- return kvm_arch_interrupt_allowed(vcpu) &&
-- !kvm_cpu_has_interrupt(vcpu) &&
-- !kvm_event_needs_reinjection(vcpu) &&
- kvm_cpu_accept_dm_intr(vcpu);
- }
-
btrfs-tree-checker-enhance-chunk-checker-to-validate-chunk-profile.patch
btrfs-inode-verify-inode-mode-to-avoid-null-pointer-dereference.patch
-kvm-x86-fix-split-irqchip-vs-interrupt-injection-window-request.patch
hid-cypress-support-varmilo-keyboards-media-hotkeys.patch
input-i8042-allow-insmod-to-succeed-on-devices-witho.patch
hid-hid-sensor-hub-fix-issue-with-devices-with-no-re.patch
+++ /dev/null
-From 71cc849b7093bb83af966c0e60cb11b7f35cd746 Mon Sep 17 00:00:00 2001
-From: Paolo Bonzini <pbonzini@redhat.com>
-Date: Fri, 27 Nov 2020 09:18:20 +0100
-Subject: KVM: x86: Fix split-irqchip vs interrupt injection window request
-
-From: Paolo Bonzini <pbonzini@redhat.com>
-
-commit 71cc849b7093bb83af966c0e60cb11b7f35cd746 upstream.
-
-kvm_cpu_accept_dm_intr and kvm_vcpu_ready_for_interrupt_injection are
-a hodge-podge of conditions, hacked together to get something that
-more or less works. But what is actually needed is much simpler;
-in both cases the fundamental question is, do we have a place to stash
-an interrupt if userspace does KVM_INTERRUPT?
-
-In userspace irqchip mode, that is !vcpu->arch.interrupt.injected.
-Currently kvm_event_needs_reinjection(vcpu) covers it, but it is
-unnecessarily restrictive.
-
-In split irqchip mode it's a bit more complicated, we need to check
-kvm_apic_accept_pic_intr(vcpu) (the IRQ window exit is basically an INTACK
-cycle and thus requires ExtINTs not to be masked) as well as
-!pending_userspace_extint(vcpu). However, there is no need to
-check kvm_event_needs_reinjection(vcpu), since split irqchip keeps
-pending ExtINT state separate from event injection state, and checking
-kvm_cpu_has_interrupt(vcpu) is wrong too since ExtINT has higher
-priority than APIC interrupts. In fact the latter fixes a bug:
-when userspace requests an IRQ window vmexit, an interrupt in the
-local APIC can cause kvm_cpu_has_interrupt() to be true and thus
-kvm_vcpu_ready_for_interrupt_injection() to return false. When this
-happens, vcpu_run does not exit to userspace but the interrupt window
-vmexits keep occurring. The VM loops without any hope of making progress.
-
-Once we try to fix these with something like
-
- return kvm_arch_interrupt_allowed(vcpu) &&
-- !kvm_cpu_has_interrupt(vcpu) &&
-- !kvm_event_needs_reinjection(vcpu) &&
-- kvm_cpu_accept_dm_intr(vcpu);
-+ (!lapic_in_kernel(vcpu)
-+ ? !vcpu->arch.interrupt.injected
-+ : (kvm_apic_accept_pic_intr(vcpu)
-+ && !pending_userspace_extint(v)));
-
-we realize two things. First, thanks to the previous patch the complex
-conditional can reuse !kvm_cpu_has_extint(vcpu). Second, the interrupt
-window request in vcpu_enter_guest()
-
- bool req_int_win =
- dm_request_for_irq_injection(vcpu) &&
- kvm_cpu_accept_dm_intr(vcpu);
-
-should be kept in sync with kvm_vcpu_ready_for_interrupt_injection():
-it is unnecessary to ask the processor for an interrupt window
-if we would not be able to return to userspace. Therefore,
-kvm_cpu_accept_dm_intr(vcpu) is basically !kvm_cpu_has_extint(vcpu)
-ANDed with the existing check for masked ExtINT. It all makes sense:
-
-- we can accept an interrupt from userspace if there is a place
- to stash it (and, for irqchip split, ExtINTs are not masked).
- Interrupts from userspace _can_ be accepted even if right now
- EFLAGS.IF=0.
-
-- in order to tell userspace we will inject its interrupt ("IRQ
- window open" i.e. kvm_vcpu_ready_for_interrupt_injection), both
- KVM and the vCPU need to be ready to accept the interrupt.
-
-... and this is what the patch implements.
-
-Reported-by: David Woodhouse <dwmw@amazon.co.uk>
-Analyzed-by: David Woodhouse <dwmw@amazon.co.uk>
-Cc: stable@vger.kernel.org
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
-Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
-Tested-by: David Woodhouse <dwmw@amazon.co.uk>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
----
- arch/x86/include/asm/kvm_host.h | 1 +
- arch/x86/kvm/irq.c | 2 +-
- arch/x86/kvm/x86.c | 18 ++++++++++--------
- 3 files changed, 12 insertions(+), 9 deletions(-)
-
---- a/arch/x86/include/asm/kvm_host.h
-+++ b/arch/x86/include/asm/kvm_host.h
-@@ -1350,6 +1350,7 @@ int kvm_test_age_hva(struct kvm *kvm, un
- void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
- int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v);
- int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
-+int kvm_cpu_has_extint(struct kvm_vcpu *v);
- int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
- int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
- void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event);
---- a/arch/x86/kvm/irq.c
-+++ b/arch/x86/kvm/irq.c
-@@ -52,7 +52,7 @@ static int pending_userspace_extint(stru
- * check if there is pending interrupt from
- * non-APIC source without intack.
- */
--static int kvm_cpu_has_extint(struct kvm_vcpu *v)
-+int kvm_cpu_has_extint(struct kvm_vcpu *v)
- {
- u8 accept = kvm_apic_accept_pic_intr(v);
-
---- a/arch/x86/kvm/x86.c
-+++ b/arch/x86/kvm/x86.c
-@@ -3053,21 +3053,23 @@ static int kvm_vcpu_ioctl_set_lapic(stru
-
- static int kvm_cpu_accept_dm_intr(struct kvm_vcpu *vcpu)
- {
-+ /*
-+ * We can accept userspace's request for interrupt injection
-+ * as long as we have a place to store the interrupt number.
-+ * The actual injection will happen when the CPU is able to
-+ * deliver the interrupt.
-+ */
-+ if (kvm_cpu_has_extint(vcpu))
-+ return false;
-+
-+ /* Acknowledging ExtINT does not happen if LINT0 is masked. */
- return (!lapic_in_kernel(vcpu) ||
- kvm_apic_accept_pic_intr(vcpu));
- }
-
--/*
-- * if userspace requested an interrupt window, check that the
-- * interrupt window is open.
-- *
-- * No need to exit to userspace if we already have an interrupt queued.
-- */
- static int kvm_vcpu_ready_for_interrupt_injection(struct kvm_vcpu *vcpu)
- {
- return kvm_arch_interrupt_allowed(vcpu) &&
-- !kvm_cpu_has_interrupt(vcpu) &&
-- !kvm_event_needs_reinjection(vcpu) &&
- kvm_cpu_accept_dm_intr(vcpu);
- }
-
pci-add-device-even-if-driver-attach-failed.patch
btrfs-tree-checker-enhance-chunk-checker-to-validate-chunk-profile.patch
btrfs-inode-verify-inode-mode-to-avoid-null-pointer-dereference.patch
-kvm-x86-fix-split-irqchip-vs-interrupt-injection-window-request.patch
arm64-pgtable-fix-pte_accessible.patch
alsa-hda-hdmi-use-single-mutex-unlock-in-error-paths.patch
alsa-hda-hdmi-fix-incorrect-locking-in-hdmi_pcm_close.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
